"""team can be nullableRevision ID: 3288ac4ef7b5Revises: d9c0f19bdf7Create Date: 2013-04-22 11:10:35.980000"""# revision identifiers, used by Alembic.revision = '3288ac4ef7b5'down_revision = 'd9c0f19bdf7'from alembic import opimport sqlalchemy as sadef upgrade():    op.alter_column("TB_CONSIGNMENT_PRODUCT", 'team_id', nullable=True,                    existing_type=sa.Integer)def downgrade():    op.alter_column("TB_CONSIGNMENT_PRODUCT", 'team_id', nullable=False,                    existing_type=sa.Integer)